2,1,3-benzothiadiazoles for use as electronic active components

ABSTRACT

The present invention describes novel 2,1,3-benzothiadiazole-containing compounds. Such compounds can be used as active components (=functional materials) in a variety of different applications which can in the widest sense be considered part of the electronics industry.

This application is a national stage application (under 35 U.S.C. 371)of PCT/EP03/06287 filed Jun. 14, 2003 which claims benefit to Germanapplication Serial No. 102 29 370.8 filed Jun. 29, 2002.

Organic compounds will in the near future be employed as activecomponents (=functional materials) in a variety of differentapplications which can in the widest sense be considered part of theelectronics industry.

In the case of the organic electroluminescence devices based on organiccomponents (for general description of the structure, cf. U.S. Pat. Nos.4,539,507 and 5,151,629) or their individual components, viz. organiclight-emission diodes (OLEDs), introduction onto the market has alreadyoccurred, as the car radios with “organic display” obtainable fromPioneer demonstrate. Further such products will be introduced shortly.However, significant improvements are still necessary here in order forthese displays to effectively compete with or to surpass the liquidcrystal displays (LCDs) which currently dominate the market.

Important conditions for practical use are, in particular, a longoperating life, a high stability to heat and a low use and operatingvoltage in order to make mobile applications possible.

The general structure of organic electroluminescence devices isdescribed, for example, in U.S. Pat. Nos. 4,539,507 and 5,151,629.

An organic electroluminescence device usually comprises a plurality oflayers which are preferably applied on top of one another by means ofvacuum methods. These individual layers are:

-   1. a support plate=substrate (usually glass or plastic film);-   2. a transparent anode (usually indium-tin oxide, ITO);-   3. a hole injection layer (=HIL): e.g. one based on copper    phthalocyanine (CuPc), conductive polymers such as polyaniline    (PANI) or polythiophene derivatives (e.g. PEDOT);-   4. a hole transport layer (=HTL): usually one based on triarylamine    derivatives;-   5. an emission layer (=EML): this layer can coincide partly with    layers 4 or 6, but usually comprises fluorescent dyes or host    molecules doped with fluorescent dyes;-   6. an electron transport layer (=ETL): mostly on the basis of    aluminum tris-8-hydroxyquinoxalinate (AIQ₃);-   7. an electron injection layer (=EIL): this layer can coincide    partly with the layer 6 or a small part of the cathode is    specifically treated or specifically deposited;-   8. a cathode: here, metals, metal combinations or metal alloys    having a low work function are generally used, e.g. Ca, Ba, Mg, Al,    In, Mg/Ag.

This overall device is, depending on the application, structured,provided with contacts and finally hermetically sealed since the life ofsuch devices is generally reduced drastically in the presence of waterand/or air.

On application of an appropriate electric potential, holes from theanode and electrons from the cathode are injected into the device andthere meet to produce an excited state. This can break down withemission of light. This light is emitted through the transparent anode.In some applications it can also be useful to reverse the arrangement,i.e. to use a (semi)transparent cathode when the anode is, for example,applied to an opaque substrate (for example a silicon chip).

In either case, the individual OLED will emit light which has a colordetermined by the EML. It is in this way possible, depending on the EML,to generate the three basic colors (blue, green, red).

A suitable combination of various individual OLEDs then makes itpossible to produce a variety of devices ranging from individuallight-emitting diodes through simple segmented displays through morecomplicated matrix displays to full-color, large-format displays/VDUs.

The EML functional materials of the abovementioned OLEDs have been orare being intensively optimized. Despite intensive optimization, thecharacteristic data of the above-described OLEDs have a number of weakpoints among which two weak points, viz. the short life of the EMLmaterials and the unfavorable efficiency-brightness curves, have provento be a particular hindrance in the implementation of OLED technology incommercial products:

1) The realistic life of the OLED materials available at present underconditions close to practice is severely limited. The life (time afterwhich the luminance has dropped to 50% of the initial luminance) in thered at constant current density and an initial luminance of 100 Cd/cm²is at best a few thousand hours. In the blue, on the other hand, usuallyonly a few hundred to at best from two to three thousand hours areachieved at an initial luminance of 100 Cd/cm².

These lives are insufficient for practical applications and hinder theintroduction of OLED devices on the market.

2) It can be seen from the efficiency-brightness curves of conventionalmaterials that the efficiency decreases greatly with increasingbrightness. This means that the high brightnesses necessary in practicecan be achieved only by means of a high power consumption. However, highpower consumptions require high battery powers in portable appliances(mobile phones, laptops, etc.). In addition, the high power consumption,which is mostly converted into heat, can lead to thermal damage to thedisplay.

These deficiencies of the prior art lead to the following objects of theinvention: provision of EML materials having a long operating life atindustrially feasible luminances in combination with flatefficiency-brightness curves, i.e. materials which display goodefficiencies even at high brightnesses.

It has surprisingly been found that particular compounds comprising the2,1,3-benzothiadiazole unit have excellent properties for use as EML (aspure material or as dopant in a host molecule matrix).

Compounds comprising the 2,1,3-benzothiadiazole unit are subject matterof the present invention. These compounds have the following properties:

-   1. The emission color of the compounds of the invention can be    adjusted over the entire visible region, i.e. from deep blue to deep    red, by choice of an appropriate substitution pattern (cf.    examples).-   2. The 2,1,3-benzothiadiazole-containing compounds of the invention    lead, when appropriate devices are used, to excellent operating    lives, as example R1 and the operating life measurements carried out    therewith show by way of example. Even after 2500 hours of    operation, no significant drop in the luminance is observed. This    unique behavior resulting from the 2,1,3-benzothiadiazole unit    indicates expected lives of >>10 000 hours.-   3. The 2,1,3-benzothiadiazole-containing compounds of the invention    when used as EML material in electroluminescence devices lead to    high efficiencies of the devices, in particular at the industrially    desirable high current densities. They make very good efficiencies    possible even at high current densities.-   4. The 2,1,3-benzothiadiazole-containing compounds of the invention    can be prepared with good reproducibility in reliably high purity    and display no batch-to-batch fluctuations.-   5. The 2,1,3-benzothiadiazole-containing compounds of the invention    have a high thermal stability. Choice of suitable substitution    patterns enables glass transition temperatures of greater than    100° C. to be achieved.-   6. The 2,1,3-benzothiadiazole-containing compounds of the invention    have excellent solubility in organic solvents. These materials can    thus be processed from solution by means of coating or printing    techniques. In a preferred embodiment, solutions can be processed    together with one or more other compounds which can have either a    low molecular weight or a relatively high or high molecular weight.    Even in conventional processing by evaporation, this property is    advantageous since it makes cleaning of the equipment or the masks    used considerably easier.

In addition to the very good properties as EMLs, it has surprisinglybeen found that particular 2,1,3-benzothiadiazole-containing compoundsdisplay excellent properties when used as ETL, as HBL (hole blockinglayer) or as host material in the EML, particularly as host material innew types of phosphorescent OLED devices. The use of these compounds inphosphorescent organic electroluminescence devices (for generalstructure and mode of operation, see: M. A. Baldo, S. Lamansky, P. E.Burrows, M. E. Tompson, S. R. Forrest, Applied Physics Letters, 1999,75, 4–6) is therefore likewise subject matter of the present invention.

Looking at the prior art in respect of ETL materials, it is conspicuousthat AIQ₃ is used virtually exclusively as ETL in all devices. Thiscompound is also, as mentioned above, frequently used additionally ashost material for the EML. Although many attempts have been made toreplace this compound by other substances, this has not been successfulto date. Up to the present time, AlQ₃ still represents the bestcompromise for the differing requirements. Thus, the compound has notonly a high thermal stability (glass transition temperature T_(g)˜190°C.), an obviously usable band position and an acceptable quantumefficiency for fluorescence in the solid state (about 40%). However, anegative aspect is the intrinsic color (absorption: yellow) on thecompound which can, particularly in the case of blue OLEDs, lead tocolor shifts as a result of fluorescence absorption and reemission. Thisis a particular disadvantage in the abovementioned device structure inwhich the light is emitted through the cathode, i.e. through the ETLtoo. Here, blue OLEDs can only be produced with severe deterioration inefficiency or color position. The usability of AlQ₃ in the new types ofphosphorescent OLEDs has also not been conclusively clarified.

A further disadvantage of the use of AIQ₃ is the instability towardholes which has now become known from the literature [cf., for example,Z. Popovic et al., Proceedings of SPIE, 1999, 3797, 310–315] and canalways lead to problems in the device in long-term use.

A critical practical disadvantage of AlQ₃ is the strongly hygroscopicnature of this compound. AlQ₃ which is synthesized and stored undernormal conditions always contains, in addition to the hydroxyquinolineligand, one molecule of water per molecule of complex [cf., for example:H. Schmidbaur et al., Z. Naturforsch. 1991, 46b, 901–911]. This isextremely difficult to remove. For use in OLEDs, AlQ₃ therefore has tobe purified in complicated, multistage sublimation processes andsubsequently be stored and handled with exclusion of water in aprotective gas atmosphere. Furthermore, large fluctuations in thequality of individual AlQ₃ batches and also poor storage stability havebeen found (S. Karg, E-MRS Conference May 30, 2000–Jun. 2, 2000Strassbourg).

AlQ₃ is likewise used as ETL in the new types of phosphorescent OLEDs,and in addition the question of the host material for the actual tripletemitters has still not been clarified at all. The use of only a fewmaterials (4,4′-biscarbazolylbiphenyl, polyvinylcarbazole and a triazolederivative) has been reported to date. However, the operating lives arestill greatly in need of optimization.

The 2,1,3-benzothiadiazole-containing compounds of the invention whichcan be used as ETL, as HBL or as host material in the EML aredistinguished, especially compared to AIQ₃ and the few host materialsknown to date for phosphorescent OLEDs, by the following properties:

-   1. They are colorless or virtually colorless; this means that their    UVA/IS absorption in the wavelength range from 400 to 700 nm is    negligible. In electroluminescence devices according to the    invention, this leads to better color purity and high efficiency.    This has the advantage that they lead, especially in blue OLEDs, to    no color shift or reduction in efficiency. A further advantage is    naturally their use as host or ETL material in inverted (cf. above)    device geometries.-   2. The 2,1,3-benzothiadiazole-containing compounds of the invention    when used as host or ETL material in the electroluminescence devices    according to the invention lead to high efficiencies which are, in    particular, independent of the current densities used. Very good    efficiencies are thus made possible even at high current densities.-   3. The 2,1,3-benzothiadiazole-containing compounds of the invention    have a high oxidation stability. When they are used in appropriate    devices according to the invention, this can lead to a significant    increase in the operating life. Furthermore, the production of these    devices becomes simpler.-   4. The 2,1,3-benzothiadiazole-containing compounds of the invention    are not noticeably hygroscopic and display a high stability to    atmospheric oxygen. Storage for a number of days or weeks in the    presence of air and water vapor does not lead to any changes in the    substances. Uptake of water by the compounds cannot be detected.    This naturally has the advantage that the substances can be    purified, transported, stored and prepared for use under simplified    conditions. Use does not, in contrast to operations employing AlQ₃,    have to take place entirely under protective gas.

In addition, as described above for use as EML materials, they can beprepared reproducibly in good yields and are thermally stable andreadily soluble in organic solvents.

The use of molecularly defined, uniform, low molecular weight (molarmass<5000 g/mol) 2,1,3-benzothiadiazole-containing compounds in OLEDs isnovel.

The invention provides compounds comprising at least one structural unitof the formula (I),

characterized in that the group G is hydrogen, fluorine and/or anorganic radical, the compounds belong to the idealized point groupS_(n), C_(n), C_(nv), C_(nh), D_(n), D_(nh) or D_(nd) with n=2, 3, 4, 5or 6, the molar masses are in the range from 450 g/mol to 5000 g/mol andthe melting points are above a temperature of 190° C., with the provisothat they do not contain a macrocycle.

The term point group as used here is a term employed in group theory, asdescribed, for example, in: F. A. Cotton, Chemical Applications of GroupTheory, 3^(rd) Edition, New York, Wiley, 1990.

For the purposes of the present invention, a macrocycle is a ring havingmore than eight ring atoms (J.-M. Lehn, Dietrich, Viont, MakrocyclicCompounds Chemistry, Weinheim, V C H Verlag, 1992 and Tetrahedron 1995,51, 9241–9284, 9767–9822).

The 2,1,3-benzothiadiazole-containing compounds of the invention arehighly suitable for use as electroluminescence materials. They canlikewise be used as dopants in many host materials.

Corresponding OLEDs in which the 2,1,3-benzothiadiazole-containingcompounds of the invention are present have both a long life and a highEL efficiency.

Prerequisites for this are the above-described symmetry properties. The2,1,3-benzothiadiazole-containing compounds have to have at least onetwo-fold or higher rotational axis since in these cases the quantumyield of the fluorescence and thus the quantum yield of theelectroluminescence is particularly large and is generally significantlyhigher than in the case of unsymmetrical compounds of the points C₁ andC_(s).

A further necessary prerequisite which suitable OLED materials have tofulfill, especially when they are applied by vacuum vapor deposition orvapor deposition in a carrier gas stream, is a molar mass in the rangefrom 450 g/mol to 5000 g/mol. If the molar mass is below theabovementioned range, the vapor pressure is so great that the vacuumequipment will be seriously contaminated even at low temperatures.Secondly, experience has shown that when the upper molar mass limit isexceeded, decomposition-free vaporization is no longer possible.

Closely linked to the molar mass are the melting points of thecompounds. These have to be above about 190° C., since only then issufficiently slow and uniform vaporization ensured and only this leadsto homogeneous, vitreous films. However, vitreous films are anindispensable prerequisite for functional OLEDs. The melting point of acompound is the temperature at which the phase transition from the solidstate to the liquid state takes place.

In addition, a sufficiently high glass transition temperature in therange above 100° C. is a necessary prerequisite for OLEDs which are tobe stable over the long term. Experience shows that in suitable organicmaterials the glass transition temperature is typically at least 60°–90°C. below the melting point, so that a melting point of 190° C.represents a lower limit for this property, too.

Furthermore, the 2,1,3-benzothiadiazole-containing compounds must notcontain any macrocyclic structure, since otherwise they will efficientlycomplex the palladium used during the synthesis and thus deactivate thecoupling catalyst. In addition, these complexes are difficult toseparate quantitatively from the product, so that purification of thecorresponding compounds is no longer feasible.

The invention likewise provides compounds of the formulae (II) and(III),

where the symbols and indices have the following meanings:

-   the radicals R are identical on each occurrence and are each H, F,    CN, a straight-chain or branched or cyclic alkyl or alkoxy group    having from 1 to 20 carbon atoms, where one or more nonadjacent CH₂    groups may be replaced by —O—, —S—, —NR¹ or —CONR²— and one or more    H atoms may be replaced by F;-   the radicals Ar are identical or different on each occurrence and    are each an aryl or heteroaryl group which has from 3 to 30 carbon    atoms and may be substituted by one or more nonaromatic radicals R;    where a plurality of substituents R, both on the same ring and on    the two different rings, may in turn together form a further    monocyclic or polycyclic ring system;-   R¹, R² are identical or different and are each H or an aliphatic or    aromatic hydrocarbon radical having from 1 to 20 carbon atoms;-   n is from 1 to 10, preferably from 1 to 6, particularly preferably    1, 2 or 3.

The property profile of the abovementioned compounds of the formula (II)or (III) in respect of the requirements for OLED applications can betailored by choice of the substituents Ar. Thus, for example,appropriate choice of the substituent Ar enables the emission color tobe set in a targeted manner over the entire visible region from deep redto deep blue (see examples).

The invention likewise provides compounds of the formula (IV),

where the symbols and indices R, Ar, R¹, R² and n are as defined aboveand m has the following meaning:

-   m is from 0 to 4, preferably 1 or 2.

Repetitive concatenation of unconjugated emitting subunits which isachieved, inter alia, by multiple repetition of 2,1,3-benzothiadiazoleunits and aromatic radicals Ar, viz. compounds of the formula (IV),leads to materials having a correspondingly short emission wavelength(blue emission color) combined with a high molar mass which result inthe abovementioned positive properties with regard to vaporization andthe glass transition point.

A balanced charge carrier injection (hole or electron injection) intothe emission layer and a balanced charge carrier transport in theemission layer are basic prerequisites for efficient OLEDs having a longlife. Since the 2,1,3-benzothiadiazole-containing compounds are, asindicated above, good electron conductors, it can in specific cases befound to be advantageous to incorporate hole-conducting units, e.g.triarylamine units as in compounds of the formulae (V) and (VI) in atargeted manner into the emitter material for the EML. Accordingly,compounds of the formula (V) and (VI) are likewise subject matter of theinvention:

where the symbols and indices R, Ar, R¹, R² and n are as defined aboveand o and p have the following meanings:

-   o is from 1 to 3, preferably 1;-   p is from 1 to 3, preferably 1.

Novel 2,1,3-benzothiadiazole-containing compounds of the formulae (V)and (VI) but also (VII), (VIII) and (IX), (X) and (XI) (see below) inwhich the 2,1,3-benzothiadiazole unit and the joined-onaromatic/heteroaromatic are strongly twisted relative to one anotherhave a low-lying HOMO (<5.5 eV relative to the vacuum level) and thus apronounced stability to oxidation. Accordingly, they are particularlysuitable for use as ETL, HBL and also as host material in the EML. Inaddition, with an appropriate choice of the aromatic/heteroaromaticradicals Ar, they are able to generate triplet states by electron-holerecombination and these can then efficiently be transferred tophosphorescent emitters present as dopants. This property isparticularly advantageous in the use of compounds of the formulae (VII)and (VII) as host material in new types of phosphorescent OLEDs.

The invention also provides compounds of the formulae (VII) and (VIII):

where the symbols and indices R, Ar, R¹ and R² are as defined above andX, o and p have the following meanings:

-   the radicals X are identical or different on each occurrence and are    each C(Ar), CR or N;-   o is from 0 to 3, preferably 1;-   p is from 1 to 3, preferably 1.

The invention also provides compounds of the formulae (IX), (X) and(XI):

where the symbols and indices X, R, Ar, R¹, R², m, n, o and p are asdefined above.

Preferred compounds of the formulae (I) to (XI) are characterized inthat the aryl or heteroaryl group Ar has from 3 to 24 carbon atoms,particularly preferably from 3 to 14 carbon atoms.

Preferred compounds of the formula (I) to (XI) are characterized in thatthe radical Ar is benzene, toluene, xylene, fluorobenzene,difluorobenzene, biphenyl, 1,2- or 1,3- or 1,4-terphenyl, tetraphenyl,naphthyl, fluorene, 9,9′-spirobifluorene, phenanthrene, anthracene,1,3,5-triphenylbenzene, pyrene, perylene, chrysene, triptycene,[2.2]paracyclophane, pyridine, pyridazine, 4,5-benzopyridazine,pyrimidine, pyrazine, 1,3,5-triazine, pyrrole, indole, 1,2,5- or1,3,4-oxadiazole, 2,2′- or 4,4′-bipyridyl, quinoline, carbazole,5,10H-dihydrophenazine, 10H-phenoxazine, phenothiazine, xanthene,9-acridine, furan, benzofuran, thiophene or benzothiophene.

Even though the information given above describes mainly use of the2,1,3-benzothiadiazole-containing compounds of the invention in OLEDs,it should be pointed out that these compounds can likewise be used verywell in the following devices:

-   1. Use as electron transport material in electrophotography.-   2. Use in photovoltaic devices, e.g. organic photodetectors or    organic solar cells, as electron acceptor material or electron    transport material.-   3. Use in organic integrated circuits (O-ICs).-   4. Use in organic field effect transistors (OFETs).-   5. Use in organic thin film transistors (OTFTs).-   6. Use in further applications, some of which have been mentioned    above, e.g. organic solid-state lasers.

These are likewise subject matter of the present invention.

To be able to be used as functional materials, the2,1,3-benzothiadiazole-containing compounds of the invention are appliedin the form of a film to a substrate, generally by means of knownmethods with which those skilled in the art are familiar, e.g. vacuumvapor deposition, vapor deposition in a carrier gas stream or fromsolution by spin coating or using various printing processes (e.g. inkjet printing, offset printing, etc).

Some examples of the 2,1,3-benzothiadiazole-containing compounds of theinvention are given below:

-   -   examples of 2,1,3-benzothiadiazole-containing compounds which        have an orange to red emission:

-   -   Examples of 2,1,3-benzothiadiazole-containing compounds which        have a green to yellow emission:

-   -   Examples of 2,1,3-benzothiadiazole-containing compounds which        have a dark blue to cyan emission:

-   -   Examples of 2,1,3-benzothiadiazole-containing compounds which        are used as ETL, HBL and as host material in the EML are:

The 2,1,3-benzothiadiazole-containing compounds were prepared bycustomary methods with which those skilled in the art are familiar, inparticular by means of palladium-catalyzed C—C coupling reactions (e.g.Suzuki coupling) or C—N coupling reactions (Hartwig-Buchwald coupling),from brominated 2,1,3-benzothiadiazoles and arylboronic acids orarylamines.

The present invention is illustrated by the following examples, withoutbeing restricted thereto. A person skilled in the art will be able toprepare further derivatives according to the invention on the basis ofthe information given without needing to make an inventive step.

1. Synthesis of 2,1,3-benzothiadiazole-containing Compounds

The following syntheses were carried out under a protected gasatmosphere unless indicated otherwise. The starting materials wereprocured from ALDRICH [2,1,3-benzothiadiazole, N-bromosuccinimide,thiopheneboronic acid, phenylboronic acid, o-tolylboronic acid,o-fluoroboronic acid, potassium phosphate, sodium cyanide,tri-tert-butylphosphine, palladium(II) acetate, Pd(PPh₃)₄] or fromALFA[4-chloro-2-methylphenylboronic acid] or prepared by literaturemethods (4,7-dibromo-2,1,3-benzothiadiazole,4,7-dibromo-5,6-dimethyl-2,1,3-benzothiadiazole: K. Pilgram, M. Zupan,R. Skiles J. Heterocycl. Chem. 1970, 7, 629).

1.1 Synthesis of Relevant Precursors EXAMPLE P1Bis-4,7-(2′-thienyl)-2,1,3-benzothiadiazole

13.52 g (11.7 mmol) of Pd(PPh₃)₄ were added to a degassed mixture of52.92 g (180.0 mmol) of 4,7-dibromo-2,1,3-benzothiadiazole, 60.14 g(470.0 mmol) of thiophene-2-boronic acid, 149.02 g (702.0 mmol) ofK₃PO₄, 1000 ml of dioxane and 1000 ml of water. After heating themixture at 80° C. for 7 hours, 4.58 g (93.6 mmol) of NaCN were added.After cooling to room temperature, the aqueous phase was separated. Theorganic phase was washed twice with H₂O and subsequently dried overNa₂SO₄. After removal of the solvent and recrystallization of the darkred solid twice from dioxane, the product was obtained in the form ofred needles. The yield, at a purity of >99.8% (HPLC), was 43.28 g (144.1mmol) (80.0%).

¹H NMR (CDCl₃, 500 MHz): [ppm]=8.11 (dd, ³J_(HH)=3.7 Hz, ⁴J_(HH)=1.0 Hz,2H), 7.89 (s, 2H), 7.46 (dd, ³J_(HH)=5.2 Hz, ⁴J_(HH)=1.0 Hz, 2H), 7.21(dd, ³J_(HH)=5.2 Hz, ³J_(HH)=3.7 Hz, 2H).

EXAMPLE P2 Bis-4,7-(5′-bromo-2′-thienyl)-2,1,3-benzothiadiazole

A solution of 7.72 g (25.7 mmol) ofbis-4,7-(2′-thienyl)-2,1,3-benzothiadiazole in 770 ml of chloroform wasadmixed with 9.51 g (54.0 mmol) of N-bromosuccinimide at roomtemperature with exclusion of light. The mixture was stirred for 6 hoursand was subsequently evaporated to a volume of 100 ml, admixed with 300ml of ethanol, the solid was filtered off with suction and washed threetimes with 100 ml of ethanol. After drying under reduced pressure (70°C., 1 mbar), the residue was recrystallized three times from DMF. Theproduct was obtained in the form of red crystals. The yield, at a purityof >99.8% (HPLC), was 10.31 g (22.5 mmol) (87.5%).

¹H NMR (DMSO-d₆, 500 MHz): [ppm]=8.17 (s, 2H), 7.95 (d, ³J_(HH)=4.2 Hz,2H), 7.40 (d, ³J_(HH)=4.2 Hz, 2H).

EXAMPLE P3Bis-4,7-(4-chloro-2-methylphenyl)-5,6-dimethyl-2,1,3-benzothiadiazole

A well-stirred, degassed suspension of 91.13 g (283.0 mmol) of4,7-dibromo-5,6-dimethyl-2,1,3-benzothiadiazole, 125.41 g (736.0 mmol)of 4-chloro-2-methylbenzenebornic acid and 300.19 g (2832.0 mmol) ofNa₂CO₃ in a mixture of 1800 ml of water and 1800 ml of dioxane wasadmixed with 809 mg (0.70 mmol) of Pd(PPh₃)₄ and subsequently refluxedfor 16 hours. After cooling, the precipitated solid was filtered offwith suction, washed three times with 300 ml of water and three timeswith 300 ml of ethanol. After drying, the solid was recrystallized twicefrom 150 ml of toluene and 260 ml of ethanol. The product was obtainedin the form of colorless crystals. The yield, at a purity of >99.6%(HPLC), was 98.57 g (238.4 mmol) (84.2%).

¹H NMR (CDCl₃, 500 MHz): [ppm]=7.28, 7.27 (2×s, 2H), 7.19, 7.18 (2×br.s, 2H), 7.06, 7.03 (2×br. s. 2H), 2.23 (s, 6H), 1.99, 1.98 (2×s, 6H).

1.2 Synthesis of Red Emitters: EXAMPLE R1Bis-4,7-(5′-phenyl-2′-thienyl)-2,1,3-benzothiadiazole

A degassed mixture of 4.53 g (10.0 mmol) ofbis-4,7-(2′-bromo-5′-thienyl)-2,1,3-benzothiadiazole (example P2), 3.66g (30.0 mmol) of benzeneboronic acid, 8.92 g (42.0 mmol) of K₃PO₄ and1.16 g (1.0 mmol) of Pd(PPh₃)₄ in 400 ml of dioxane and 400 ml of waterwas heated at 80° C. for 7 hours. After cooling, the mixture was admixedwith 0.49 g (10.0 mmol) of NaCN, and after stirring for 15 minutes theaqueous phase was separated off, the organic phase was washed twice withH₂O and subsequently dried over Na₂SO₄. After removal of the solvent andrecrystallization from DMF twice, the product was obtained in the formof red needles. The yield, at a purity of >99.9% (HPLC), was 4.31 g (9.5mmol) (95.2%). ¹H NMR (DMSO-d₆, 500 MHz): [ppm]=8.21 (d, ³J_(HH)=4.0 Hz,2H), 8.18 (s, 2H), 7.82 (m, 2H), 7.69 (d, ³J_(HH)=4.0 Hz, 2H), 7.47 (m,4H), 7.37 (m, 4H). Mp.: 229° C.

EXAMPLE R2Bis-4,7-(5′-(2-methylphenyl)-2′-thienyl)-2,1,3-benzothiadiazole

This was prepared in a manner analogous to example R1. Instead of thebenzeneboronic acid, 4.08 g (30.0 mmol) of 2-methylphenylboronic acidwere used. The yield, at a purity of >99.9% (HPLC), was 4.37 g (9.1mmol) (91.0%).

¹H NMR (CDCl₃, 500 MHz): [ppm]=8.15 (d, ³J_(HH)=4.0 Hz, 2H), 7.91 (s,2H), 7.52 (m, 2H), 7.29 (m, 6H), 7.19 (d, ³J_(HH)=4.0 Hz, 2H), 2.53 (s,6H). Mp.: 198° C.

EXAMPLE R3Bis-4,7-(5′-(2-fluorophenyl)-2′-thienyl)-2,1,3-benzothiadiazole

This was prepared in a manner analogous to example R1. Instead of thebenzeneboronic acid, 4.20 g (30.0 mmol) of 2-fluorophenylboronic acidwere used. The yield, at a purity of >99.9% (HPLC), was 4.28 g (7.2mmol) (72.0%).

¹H NMR (CDCl₃, 500 MHz): [ppm]=8.14 (dd, ³J_(HH)=4.0 Hz, ⁶J_(HF)=0.67Hz, 2H), 7.92 (s, 2H), 7.72 (m, 2H), 7.59 (dd, ³J_(HH)=4.0 Hz,⁵J_(HF)=1.34 Hz, 2H), 7.21 (m, 6H). Mp.: 193° C.

EXAMPLE R12 Bis-4,7-(5′-(2-biphenyl)-2′-thienyl)-2,1,3-benzothiadiazole

This was prepared in a manner analogous to example R1. Instead of thebenzeneboronic acid, 5.90 g (30.0 mmol) of 2-biphenylboronic acid wereused. The yield, at a purity of >99.9% (HPLC), was 5.11 g (8.5 mmol)(84.5%).

¹H NMR (CDCl₃, 500 MHz): [ppm]=8.88 (dd, 2H), 7.68 (s, 2H), 7.66 (m,2H), 7.40 (m, 6H), 7.32 (m, 10H), 6.68 (d, 2H). Mp.: 191° C.

1.3 Synthesis of Green Emitters: EXAMPLE G6Bis-4,7-(2-spiro-9,9′-bifluorenyl)-2,1,3-benzothiadiazole

This was prepared in a manner analogous to example R1. Instead of thebenzeneboronic acid, 10.81 g (30.0 mmol) ofspiro-9,9′-bifluorene-2-boronic acid were used.

The yield, at a purity of >99.9% (HPLC), was 5.58 g (7.3 mmol) (73.0%).

¹H NMR (CDCl₃, 500 MHz): [ppm]=7.93 (s, 2H), 7.84 (m, 4H), 7.80 (m, 2H),7.67 (m, 2H), 7.48 (m, 2H), 7.38 (m, 4H), 7.35 (m, 2H), 7.11 (m, 6H),6.85 (m, 2H), 6.71 (m, 6H). Mp. >350° C.

1.4 Synthesis of Blue Emitters: EXAMPLE B1Bis-4,7-(2-methylterphenyl)-5,6-dimethyl-2,1,3-benzothiadiazole

A well-stirred, degassed suspension of 41.34 g (100.0 mmol) ofbis-4,7-(4-chloro-2-methylphenyl)-5,6-dimethyl-2,1,3-benzothiadiazole,55.51 g (280 mmol) of biphenyl-4-boronic acid and 136.84 g (420 mmol) ofCs₂CO₃ in 1500 ml of dioxane was admixed with 243 mg (1.2 mmol) oftri-tert-butylphosphene and 225 mg (1.0 mmol) of palladium(II) acetateand subsequently refluxed for 16 hours. After cooling, 1500 ml of waterwere added and the precipitate formed was washed three times with 300 mlof water and three times with 300 ml of ethanol. After drying, the solidwas recrystallized four times from 300 ml of toluene and 100 ml ofethanol. The product was obtained in the form of colorless crystals. Theyield, at a purity of >99.9% (HPLC), was 53.14 g (81.9 mmol) (81.9%).

¹H NMR (CDCl₃, 500 MHz): [ppm]=7.88 (m, 4H), 7.69 (m, 4H), 7.61 (m, 4H),7.47 (m, 4H), 7.37 (m, 2H), 7.26, 7.25 (2×s, 2H), 7.14, 7.13 (2×br. s,2H), 7.09, 7.08 (2×br. s, 2H), 2.22 (s, 6H), 1.97, 1.96 (2×s, 6H). Mp.:281° C.

2. Production and Characterization of Organic ElectroluminescenceDevices Comprising the Compounds According to the Invention

LEDs were produced by the general method outlined below. This naturallyhad to be adapted in each individual case to the individualcircumstances (e.g. layer thickness variation to achieve optimalefficiency or color).

2.1 General Method of Producing OLEDs

After the ITO-coated substrate (e.g. glass supports, PET film) have beencut to the correct size, they are cleaned in a number of cleaning stepsin an ultrasonic bath (e.g. soap solution, Millipore water,isopropanol). To dry the substrates, they are blown with an N₂ gun andstored in a desiccator. Before vapor deposition of the organic layers,the substrates are treated by means of an ozone plasma apparatus forabout 20 minutes. It can be advisable to use a polymeric hole injectionlayer as first organic layer. This is generally a conjugated, conductivepolymer, e.g. a polyaniline derivative (PANI) or a polythiophenederivative (e.g. PEDOT, BAYTRON P™ from BAYER). This is then applied byspin coating.

The organic layers are applied in order by vapor deposition in ahigh-vacuum unit. The layer thickness of the respective layer and thedeposition rate are monitored and set by means of a crystal oscillator.It is also possible, as described above, for individual layers toconsist of more than one compound, i.e. in general, a host material canbe doped with a guest material. This is achieved by covaporization fromtwo or more sources.

Electrodes are then applied to the organic layers. This is generallyachieved by thermal vapor deposition (Balzer BA360 or Pfeiffer PL S500).

The transparent ITO electrode is subsequently connected as anode and themetal electrode (e.g. Ca, Yb, Ba—Al) is connected as cathode and thedevice parameters are determined.

2.2 Process for Producing Red OLEDs EXAMPLE 1 Red OLED with EmitterMaterial from Example R1

Using a procedure analogous to the abovementioned general method, ared-emitting OLED having the following structure was produced:

PEDOT 20 nm (applied by spin coating from water; PEDOT procured fromBAYER AG; poly[3,4-ethylenedioxy-2,5-thiophene] MTDATA 20 nm(vapor-deposited; MTDATA procured from SynTec; tris-4,4′,4″-(3-methylphenylphenylamino)triphenylamine) S-TAD 20 nm (vapor-deposited;S-TAD prepared as described in WO99/12888;2,2′,7,7′-tetrakis(diphenylamino)-9,9′-spirobifluorene) AIQ₃ 30 nm(vapor-deposited; AIQ₃ procured from SynTec;tris(quinoxalinato)aluminum(III)) and doped with R1 10% by weight(vapor-deposited; bis-4,7-(5′-phenyl-2′-thienyl)-2,1,3- benzothiadiazoleprepared as described in example R1) AIQ₃ 10 nm (vapor-deposited; AIQ₃procured from SynTec; tris(quinoxalinato)aluminum(III)) Ba 10 nm ascathode Ag 100 nm as cathode protection layerThis unoptimized OLED was characterized in a standard fashion; themeasured data are shown in FIGS. 1–3. Apart from the flatness of theefficiency curve, which means that high efficiencies can still beachieved even at very high brightnesses (e.g. 10 000 Cd/m²), theexcellent operating life of this OLED is a great advantage.

EXAMPLE 2 Red OLED with Emitter Material from Example R12

Using a procedure analogous to the abovementioned general method, ared-emitting OLED having the following structure was produced:

PEDOT 20 nm (applied by spin coating from water; PEDOT procured fromBAYER AG; poly[3,4-ethylenedioxy-2,5-thiophene] MTDATA 20 nm(vapor-deposited; MTDATA procured from SynTec; tris-4,4′,4″-(3-methylphenylphenylamino)triphenylamine) S-TAD 20 nm (vapor-deposited;S-TAD prepared as described in WO99/12888;2,2′,7,7′-tetrakis(diphenylamino)-9,9′-spirobifluorene) AIQ₃ 30 nm(vapor-deposited; AIQ₃ procured from SynTec;tris(quinoxalinato)aluminum(III)) and doped with R12 10% by weight(vapor-deposited; bis-4,7-(5′-(2-biphenyl)-2′-thienyl)-2,1,3-benzothiadiazole prepared as described in example R12) AIQ₃ 10 nm(vapor-deposited; AIQ₃ procured from SynTec;tris(quinoxalinato)aluminum(III)) Ba 10 nm as cathode Ag 100 nm ascathode protection layerThis unoptimized OLED was characterized in a standard fashion; themeasured data are shown in FIGS. 4–6. Apart from the flatness of theefficiency curve, which means that high efficiencies can still beachieved even at very high brightnesses (e.g. 10 000 Cd/m²), theexcellent operating life of this OLED is a great advantage.

2.3 Method of Producing Blue OLEDs EXAMPLE 3 Blue OLED with EmitterMaterial from Example B1

Using a procedure analogous to the abovementioned general method, ablue-emitting OLED having the following structure was produced:

PEDOT 20 nm (applied by spin coating from water; PEDOT procured fromBAYER AG; poly[3,4-ethylenedioxy-2,5-thiophene] MTDATA 20 nm(vapor-deposited; MTDATA procured from SynTec; tris-4,4′,4″-(3-methylphenylphenylamino)triphenylamine) S-TAD 20 nm (vapor-deposited;S-TAD prepared as described in WO99/12888;2,2′,7,7′-tetrakis(diphenylamino)-9,9′-spirobifluorene) S-DPVBi 30 nm(vapor-deposited; S-DPVBi prepared as described by H. Spreitzer, H.Schenk, J. Salbeck, F. Weissoertel, H. Riel. W. Ries, Proceedings ofSPIE, 1999, Vol. 3797; 2,2′,7,7′-tetrakis(2,2′-diphenylvinyl)spiro-9,9′-bifluorene) and doped with B1 10% by weight (vapor-deposited;5,6-dimethylbis-4,7-(2,5- dimethylphenyl)-2,1,3-benzothiadiazoleprepared as described in example B1), doped into the above S-DPVBi layerAIQ₃ 10 nm (vapor-deposited; AIQ₃ procured from SynTec;tris(quinoxalinato)aluminum(III)) Ba 10 nm as cathode Ag 100 nm ascathode protection layerThis unoptimized OLED was characterized in a standard fashion; themeasured data are shown in FIGS. 7 and 8. Apart from the color, atremendous advantage of this OLED is the flatness of the efficiencycurve, which means that high efficiencies can still be achieved even atvery high brightnesses (e.g. 10 000 Cd/m²). This is of criticalimportance especially for use in passive matrix displays.

1. A compound which belong to the idealized point group S_(n), C_(n),C_(nv), C_(nh), D_(n), D_(nh) or D_(nd) with n=2, 3, 4, 5 or 6, themolar masses are in the range from 450 g/mol to 5000 g/mol and themelting points are above a temperature of 190° C., having the Formula(II) or (III),

where the symbols and indices have the following meanings: the radicalsR are identical on each occurrence and are each H, F, CN, astraight-chain or branched or cyclic alkyl or alkoxy group having from 1to 20 carbon atoms, where one or more nonadjacent CH₂ groups may bereplaced by —O—, —S—, —NR¹ or —CONR²— and one or more H atoms may bereplaced by F; the radicals Ar are identical or different on eachoccurrence and are each an aryl or heteroaryl group which has from 3 to30 carbon atoms and may be substituted by one or more nonaromaticradicals R; where a plurality of substituents R, both on the same ringand on the two different rings, may in turn together form a furthermonocyclic or polycyclic ring system; R¹, and R² are identical ordifferent and are each H or an aliphatic or aromatic hydrocarbon radicalhaving from 1 to 20 carbon atoms; n2 is from 3 to 10, n1 is from 1 to10, and with the proviso that they do not contain a macrocycle.
 2. Acompound which belong to the idealized point group S_(n), C_(n), C_(nv),D_(n), D_(nh) or D_(nd) with n=2, 3, 4, 5 or 6, the molar masses are inthe range from 450 g/mol to 5000 g/mol and the melting points are abovea temperature of 190° C., described by the formula (IV)

where the symbols and indices have the following meanings: the radicalsR are identical on each occurrence and are each H, F, CN, astraight-chain or branched or cyclic alkyl or alkoxy group having from 1to 20 carbon atoms, where one or more nonadjacent CH₂ groups may bereplaced by —O—, —S—, —NR¹ or —CONR²— and one or more H atoms may bereplaced by F; the radicals Ar¹ are identical or different on eachoccurrence and are each an aryl or heteroaryl group which are benzene,toluene, xylene, fluorobenzene, difluorobenzene, biphenyl, 1,2- or 1,3-or 1,4-terphenyl, tetraphenyl, naphthyl, fluorene, 9,9′-spirobifluorene,phenanthrene, anthracene, 1,3,5-triphenylbenzene, pyrene, perylene,chrysene, triptycene, [2.2]paracyclophane, pyridine, pyridazine,4,5-benzopyridazine, pyrimidine, pyrazine, 1,3,5-triazine, pyrrole,indole, 1,2,5- or 1,3,4-oxadiazole, 2,2′- or 4,4′-bipyridyl, quinoline,carbazole, 5,10H-dihydrophenazine, 10H-phenoxazine, phenothiazine,xanthene, 9-acridine, furan, benzofuran, or benzothiophene which may besubstituted by one or more nonaromatic radicals R; where a plurality ofsubstituents R, both on the same ring and on the two different rings,may in turn together form a further monocyclic or polycyclic ringsystem; R¹, and R² are identical or different and are each H or analiphatic or aromatic hydrocarbon radical having from 1 to 20 carbonatoms; m is from 0 to 4; n1 is from 1 to
 10. 3. A compound which belongto the idealized point group S_(n), C_(n), C_(nv), D_(n), D_(nh) orD_(nd) with n=2, 3, 4, 5 or 6, the molar masses are in the range from450 g/mol to 5000 g/mol and the melting points are above a temperatureof 190° C., described by the formula (V), (VI), (VII), (VIII), (IX) (X)or (XI)

where the symbols and indices have the following meanings: the radicalsR are identical on each occurrence and are each H, F, CN, astraight-chain or branched or cyclic alkyl or alkoxy group having from 1to 20 carbon atoms, where one or more nonadjacent CH₂ groups may bereplaced by —O—, —S—, —NR¹ or —CONR²— and one or more H atoms may bereplaced by F; the radicals Ar are identical or different on eachoccurrence and are each an aryl or heteroaryl group which has from 3 to30 carbon atoms and may be substituted by one or more nonaromaticradicals R; where a plurality of substituents R, both on the same ringand on the two different rings, may in turn together form a furthermonocyclic or polycyclic ring system; the radicals Ar³ are identical ordifferent on each occurrence and are each an aryl or heteroaryl groupwhich are toluene, xylene, fluorobenzene, difluorobenzene, biphenyl,1,2- or 1,3- or 1,4-terphenyl, tetraphenyl, naphthyl, fluorene,9,9′-spirobifluorene, phenanthrene, anthracene, 1,3,5-triphenylbenzene,pyrene, perylene, chrysene, triptycene, [2.2]paracyclophane, pyridine,pyridazine, 4,5-benzopyridazine, pyrimidine, pyrazine, 1,3,5-triazine,pyrrole, indole, 1,2,5- or 1,3,4-oxadiazole, 2,2′- or 4,4′-bipyridyl,quinoline, carbazole, 5,10H-dihydrophenazine, 10H-phenoxazine,phenothiazine, xanthene, 9-acridine, furan, benzofuran, thiophene orbenzothiophene which may be substituted by one or more nonaromaticradicals R; where a plurality of substituents R, both on the same ringand on the two different rings, may in turn together form a furthermonocyclic or polycyclic ring system; the radicals Ar² are identical ordifferent on each occurrence and are each an aryl or heteroaryl groupwhich has from 3 to 30 carbon atoms and may be substituted by one ormore nonaromatic radicals R³; where a plurality of substituents R³, bothon the same ring and on the two different rings, may in turn togetherform a further monocyclic or polycyclic ring system; R¹, and R² areidentical or different and are each H or an aliphatic or aromatichydrocarbon radical having from 1 to 20 carbon atoms; the radicals X areidentical or different on each occurrence and are each C(Ar), CR or N;the radicals R³ are identical on each occurrence and are each H, F, CN,a straight-chain or branched or cyclic alkyl having from 1 to 20 carbonatoms, where one or more nonadjacent CH₂ groups may be replaced by —O—,—S—, —NR¹ or —CONR²— and one or more H atoms may be replaced by F; n1 isfrom 1 to 10; o is from 1 to 3; and p is from 1 to
 3. 4. The compound asclaimed in claim 3, which is described by the formula (VII) or (VIII).5. The compound as claimed in claim 3, where the compound is describedby the formula (IX), (X), or (XI), and the molar masses are in the rangefrom 450 g/mol to 5000 g/mol and the melting points are above atemperature of 190° C., with the proviso that they do not contain amacrocycle.
 6. The compound as claimed in claim 1, characterized in thatthe radical Ar is benzene, toluene, xylene, fluorobenzene,difluorobenzene, biphenyl, 1,2- or 1,3- or 1,4-terphenyl, tetraphenyl,naphthyl, fluorene, 9,9′-spirobifluorene, phenanthrene, anthracene,1,3,5-triphenylbenzene, pyrene, perylene, chrysene, triptycene,[2.2]paracyclophane, pyridine, pyridazine, 4,5-benzopyridazine,pyrimidine, pyrazine, 1,3,5-triazine, pyrrole, indole, 1,2,5- or1,3,4-oxadiazole, 2,2′- or 4,4′-bipyridyl, quinoline, carbazole,5,10H-dihydrophenazine, 10H-phenoxazine, phenothiazine, xanthene,9-acridine, furan, benzofuran, thiophene or benzothiophene.
 7. Anelectronic component comprising at least one compound as claimed inclaim
 1. 8. An electronic component comprising at least one compound asclaimed in claim
 2. 9. An electronic component comprising at least onecompound as claimed in claim
 3. 10. The compound as claimed in claim 1,wherein n1 is from 1 to
 6. 11. The compound as claimed in claim 1,wherein n1 is from 1,2 or
 3. 12. The compound as claimed in claim 2,wherein m is from 1 or 2 and n1 is from 1, 2, or3.
 13. The compound asclaimed in claim 3, wherein the compound is of the formula (V) or (VI)and n1 is from 1, 2 or 3; o is 1; and p is
 1. 14. The compound asclaimed in claim 5, wherein m is from 1 or 2; n1 is from 1, 2 or
 3. 15.The compound as claimed in claim 14, characterized in that the radicalAr is benzene, toluene, xylene, fluorobenzene, difluorobenzene,biphenyl, 1,2- or 1,3- or 1,4-terphenyl, tetraphenyl, naphthyl,fluorene, 9,9′-spirobifluorene, phenanthrene, anthracene,1,3,5-triphenylbenzene, pyrene, perylene, chrysene, triptycene,[2.2]paracyclophane, pyridine, pyridazine, 4,5-benzopyridazine,pyrimidine, pyrazine, 1,3,5-triazine, pyrrole, indole, 1,2,5- or1,3,4-oxadiazole, 2,2′- or 4,4′-bipyridyl, quinoline, carbazole,5,10H-dihydrophenazine, 10H-phenoxazine, phenothiazine, xanthene,9-acridine, furan, benzofuran, thiophene or benzothiophene.
 16. Anorganic electroluminescence and/or electrophosphorescence devices whichcomprises the compound as claimed in claim
 1. 17. An emission layer(EML), a host material in electroluminescence and/orelectrophosphorescence devices, as electron transport layers (ETLs)and/or hole-blocking layers (HBLs) which comprises the compound asclaimed in claim
 1. 18. An electron transport material inelectrophotography, electron acceptor material or electron transportmaterial in photovoltaic devices which comprises the compound as claimedin claim
 1. 19. An organic photodetector, organic solar cells, atransport material in organic ICs (organic integrated circuits), atransport material and/or dopant in organic field effect transistors(OTFTs), a transport material and/or dopant in organic thin-filmtransistors or an organic solid-state lasers which comprises thecompound as claimed in claim
 1. 20. An electronic component comprisingat least one compound as claimed in claim
 2. 21. An electronic componentcomprising at least one compound as claimed in claim 3.